A flat coil is in a uniform magnetic field.The magnetic flux through the coil is greatest when the plane of its area is
A)parallel to the magnetic field.
B)at 45° with the magnetic field.
C)perpendicular to the magnetic field.

Question

Quizplus · Accepted Answer

The magnetic flux through a coil is given by the product of the magnetic field strength, the area of the coil, and the cosine of the angle between the magnetic field and the normal to the coil's surface (Φ=BAcosθ). Since the cosine of 90° (perpendicular) is 0, the magnetic flux is maximum when the angle is 0° (parallel) and minimum when the angle is 90° (perpendicular). Therefore, the best choice is C, when the plane of the coil's area is perpendicular to the magnetic field.

A Flat Coil Is in a Uniform Magnetic Field